bad maf, pcm, or grounds

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04-02-2007, 10:16 PM

#16

LiENUS

Registered User

Join Date: Jul 2005

Location: Baton Rouge, LA

Posts: 747

Quote:

Originally Posted by evilundisguised

My MAF is disconnected, and the only difference is it that the engine runs in speed density mode. Pretty well, too... definitely not limping. Rich mode...?

Is it tuned for a disconnected MAF?

04-02-2007, 10:23 PM

#17

evilundisguised

Registered User

Join Date: Feb 2006

Posts: 302

Quote:

Originally Posted by LiENUS

Is it tuned for a disconnected MAF?

If you're asking if I've turned off any of the MAF diagnostic switches, then no. So yes, it currently has a lit SES light. And closed loop operation still keeps the AFR within .2 of stoich while cruising, usually 14.8.

04-02-2007, 11:10 PM

#18

sbs

Registered User

Join Date: Feb 2004

Location: VA

Posts: 1,155

Quote:

Originally Posted by LiENUS

You have provided nothing to this discussion.

You, on the other hand, have contributed a lot. A lot of false information.

Quote:

Originally Posted by LiENUS

You have provided nothing to this discussion. If you unplug the MAF and do not tune out the error codes the engine will throw a CEL and pop on the fans. That usually means limp home mode. Yes it will continue to run fine, no it won't blow up.

Which makes this guy an idiot:

Quote:

Originally Posted by LiENUS

it would first off switch to speed density mode (using map sensor) and secondly it would kick into limp home mode, and pull timing/run rich to keep from burning the engine up.

And this guy also:

Quote:

Originally Posted by LiENUS

It spits out a check engine light which puts you in limp home mode

So, does it or doesn't it go into "limp home mode"?

If it does, then please show us where in the manual it describes how it goes into limp home mode when DTC 48 is set. Surely it's documented in the manual. Or is it a secret that only you know?

04-02-2007, 11:15 PM

#19

sbs

Registered User

Join Date: Feb 2004

Location: VA

Posts: 1,155

Quote:

Originally Posted by LiENUS

But your fuel economy is going to suck and it ain't gonna run right, especially if you have changed ANYTHING on the induction or exhaust. If your airfilter is clogged up and needs to be changed its going to run ****ty if your MAF is descreened, its going to run ****ty. The SD tune is for a stock engine with full emissions equipment so if hes changed anything on the exhaust or intake its going to run ****ty, hell I wouldn't be surprised if using a fram paper filter instead of an AC Delco paper filter caused a minor change to the volumetric efficency of the engine.

My car with aftermarket exhaust and a Fram paper filter runs fine in SD mode with the stock SD tune.

My BLMs in SD mode with the stock tune are no farther off than my BLMs in MAF mode with the same stock tune.

04-02-2007, 11:38 PM

#20

LiENUS

Registered User

Join Date: Jul 2005

Location: Baton Rouge, LA

Posts: 747

Quote:

Originally Posted by steve9899

You, on the other hand, have contributed a lot. A lot of false information.

Which makes this guy an idiot:

And this guy also:

So, does it or doesn't it go into "limp home mode"?

If it does, then please show us where in the manual it describes how it goes into limp home mode when DTC 48 is set. Surely it's documented in the manual. Or is it a secret that only you know?

Well since I'm 800 miles from home I can't very well pull the manual out now can I? Why don't you point out in the manual where it says to run without the MAF sensor. If you'd like give me 2 months Il'l do a complete disassembly of the ECU code and translate it to C and post it here for you but after I make you look like an *** you have to pay my consulting fee. 150 per coding hour should only translate into roughly 15-20 coding hours thats cheap considering I'm not charging for the disassembly and documentation of how the code functions, nor would I be providing those or better yet pull out "TFM" and post relevant section.

Last edited by LiENUS; 04-02-2007 at 11:49 PM.